To find sites that are appropriate for an inbound link request, you should:
Consider the sites you find useful, entertaining, and informative.
Use the Web's taxonomic directories to find sites in your category and in related categories
Use specialized searching syntax to find the universe of sites that search engines such as Google regard as "related" to yours. For example, the search related: www.digitalfieldguide.com produces a list of sites that Google thinks are similar to www.digitalfieldguide.com.